BIOS and UEFI Bootable USB

Using dd

In GNU/Linux

Tip: Check that the USB flash installation media is not mounted with lsblk.

Note: Use /dev/sdx instead of /dev/sdx1, and adjust x to reflect the targeted device.

# dd bs=4M if=/path/to/archlinux.iso of=/dev/sdx && sync

In Mac OS X

To be able to use dd on your USB device on a Mac you have to do some special maneuvers. First of all insert your usb device, OS X will automount it, and in Terminal.app run:

$ diskutil list

Figure out what your USB device is called with mount or sudo dmesg | tail (e.g. /dev/disk1) and unmount the partitions on the device (i.e., /dev/disk1s1) while keeping the device proper (i.e., /dev/disk1):

$ diskutil unmountDisk /dev/disk1

Now we can continue in accordance with the instructions above (but use bs=8192 if you are using the OS X dd, the number comes from 1024*8).